CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Functional Plant Biology   
Functional Plant Biology
Journal Banner
  Plant Function & Evolutionary Biology
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Board
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Research Fronts
Reviews
Evolutionary Reviews
Sample Issue
For Authors
General Information
Notice to Authors
Submit Article
Open Access
For Referees
Referee Guidelines
Review Article
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter youtube

red arrow PrometheusWiki
blank image
PrometheusWiki
Protocols in ecological and environmental plant physiology

 

Article << Previous     |     Next >>   Contents Vol 28(3)

Carbon and water economy of Australian NAD-ME and NADP-ME C4 grasses

Oula Ghannoum, Susanne von Caemmerer and Jann P. Conroy

Australian Journal of Plant Physiology 28(3) 213 - 223
Published: 2001

Abstract

C4 grasses are grouped into three biochemical subtypes,NAD malic enzyme (NAD–ME), NADP malic enzyme (NADP–ME)and phosphoenolpyruvate carboxykinase (PCK), possessingcharacteristic leaf anatomy, biochemistry and physiology. This studyinvestigates the physiological implications of these differences by comparing growth, water use efficiency (WUE, dry matter gain per unit water transpired) and gas exchange characteristics of NAD–MEand NADP–ME C4 grasses belonging to threetaxonomic groups (main Chloroid assemblage, Paniceae and Andropogoneae). Wegrew 28 C4 grasses from seeds for 6 weeks in aglasshouse under ample water and nutrients in winter and summer. Theinter-specific variation in plant dry mass (30-fold) was much greater thanthat in WUE (2-fold). There was no significantdifference in average WUE between NAD–ME andNADP–ME grasses. Average plant dry mass andWUE were highest in the Paniceae (mostlyNADP–ME), lowest in the Andropogoneae (NADP–ME) and intermediate in the Chloroid (NAD–ME). CO2assimilation rate (A), stomatal conductance(g) and the ratio of intercellular to ambient CO2 partial pressure (pi/p a )were measured under standard conditions at high light. AverageA and g were slightly higher inNADP–ME than NAD–ME grasses, but pi/p awas similar for the two subtypes. A did not differbetween winter and summer experiments in spite of a 3-fold difference inmaximal daily irradiance. Dry matter accumulation correlated positively withleaf area ratio (LAR; plant leaf area per unit plant drymass) and specific leaf area (SLA; leaf area per unitleaf dry mass) in NAD–ME, but not NADP–ME, grasses.Variation in A (expressed on a per area basis) did notcorrelate with biomass accumulation or SLA. Whenexpressed on a dry mass basis, A correlated withSLA in all C4 grasses. This studyshows that there is large inter-specific variation in growth among the C4 grasses, but average WUE andA/g are similar forNAD–ME and NADP–ME species under well-wateredconditions.



Full text doi:10.1071/PP00078

© CSIRO 2001

blank image
Subscriber Login
Username:
Password:  

 
PDF (299 KB) $25
 Export Citation
 Print
  
    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2014